Toner for developing electrostatic image containing higher and lower molecular weight polymer components

- Canon

An electrophotographic toner composition suitable for heat-fixation and showing good storage characteristics is constituted by polymer components, a colorant and a metal-containing organic compound. The toner composition shows a melt index (at 125.degree. C., 10 kg-load) of 5-25 g/10 min., and the polymer components are characterized by (a) containing substantially no THF (tetrahydrofuran)-insoluble content, (b) including a THF-soluble content thereof providing a GPC (gel permeation chromatography) chromatogram showing i) a main peak in a molecular weight region of 2.times.10.sup.3 -3.times.10.sup.4, and a sub-peak or shoulder in a molecular weight region of at least 10.sup.5, and ii) an areal percentage of 3-10% in a molecular weight region of at least 10.sup.6, and (c) including a polymer component (H) in a molecular weight region of at least 10.sup.5 obtained by polymerization using a polyfunctional polymerization initiator and a monofunctional polymerization initiator.

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Claims

1. A toner composition for developing an electrostatic image, comprising: polymer components, a colorant and a metal-containing organic compound, wherein

the composition shows a melt index (at 125.degree. C., 10 kg-load) of 5-25 g/10 min., and
the polymer components are characterized by
(a) having a THF (tetrahydrofuran)-insoluble content from 0 to 5 wt. %,
(b) including a THF-soluble content thereof providing a GPC (gel permeation chromatography) chromatogram showing
i) a main peak in a molecular weight region of 2.times.10.sup.3 -3.times.10.sup.4, and a sub-peak or shoulder in a molecular weight region of at least 10.sup.5, and
ii) an areal percentage of 3-10% in a molecular weight region of at least 10.sup.6, and
(c) including a polymer component (H) providing the sub-peak or shoulder in the molecular weight region of at least 10.sup.5 obtained by polymerization using a polyfunctional polymerization initiator and a mono-functional polymerization initiator, said polymer component (H) comprising a monomer unit (A) having at least one species of carboxyl group, carboxylic acid salt group or carboxylic anhydride group.

2. A toner composition for developing an electrostatic image, comprising: polymer components, a colorant and a metal-containing organic compound, wherein

the composition shows a melt index (at 125.degree. C., 10 kg-load) of 5-25 g/10 min., and
the polymer components are characterized by
(a) having a THF (tetrahydrofuran)-insoluble content from 0 to 5 wt. %,
(b) including a THF-soluble content thereof providing a GPC (gel permeation chromatography) chromatogram showing
i) a main peak in a molecular weight region of 2.times.10.sup.3 -3.times.10.sup.4, and a sub-peak or shoulder in a molecular weight region of at least 10.sup.5, and
ii) an areal percentage of 3-10% in a molecular weight region of at least 10.sup.6, and
(c) including a polymer component (H) providing the sub-peak or shoulder in the molecular weight region of at least 10.sup.5 obtained by polymerization using a polyfunctional polymerization initiator and a mono-functional polymerization initiator, said polymer component (H) comprising a monomer unit (A) having at least one species of carboxyl group, carboxylic acid salt group or carboxylic anhydride group and a crosslinking monomer unit (B) in a ratio satisfying 20<A/B<10,000 by weight.

3. The toner composition according to claim 1 or claim 2, which has dynamic visco-elasticities including a dynamic loss modulus (G") and a dynamic loss tangent (tan.delta.) which is a ratio of G" to a dynamic storage modulus (G') at 200.degree. C. and 150.degree. C. satisfying the following conditions:

1.ltoreq.tan.delta..sub.150 /tan.delta..sub.200.ltoreq.2,

4. The toner composition according to claim 1 or claim 2, which has a THF-insoluble content of at most 3 wt. %.

5. The toner composition according to claim 1 or claim 2, wherein the polymer components include a low-molecular weight fraction having molecular weights of below 10.sup.5 showing an acid value of at most 3.0.

6. The toner composition according to claim 5, wherein the polymer components include a low-molecular weight fraction having molecular weights of below 10.sup.5 showing an acid value of at most 1.5.

7. The toner composition according to claim 5, wherein the polymer components include a high-molecular weight fraction having molecular weights of at least 10.sup.5 showing an acid value above 3.0.

8. The toner composition according to claim 7, wherein the polymer components include a high-molecular weight fraction having molecular weights of at least 10.sup.5 showing an acid value above 5.0.

9. The toner composition according to claim 1 or claim 2, wherein the polymer components include a high-molecular weight fraction having molecular weights of at least 10.sup.5 containing 1-20 wt. % of a carboxyl group-containing monomer unit.

10. The toner composition according to claim 9, wherein the polymer components include a high-molecular weight fraction having molecular weights of at least 10.sup.5 containing 3-15 wt. % of a carboxyl group-containing monomer unit.

11. The toner composition according to claim 1 or claim 2, wherein the polymer components have a glass transition temperature of 50.degree.-70.degree. C.

12. The toner composition according to claim 11, wherein the polymer components have a glass transition temperature of 55.degree.-65.degree. C.

13. The toner composition according to claim 1 or claim 2, which has a melt index of 8-20 g/10 min.

14. The toner composition according to claim 1 or claim 2, wherein the polymer component (H) contains at most 1 wt. % of a crosslinking monomer unit.

15. The toner composition according to claim 14, wherein the polymer component (H) contains 0.001-0.05 wt. % of a crosslinking monomer unit.

16. The toner composition according to claim 1 or claim 2, which further comprises a low-molecular weight wax having a weight-average molecular weight of at most 3.times.10.sup.4.

17. The toner composition according to claim 16, which contains 1-20 wt. parts of the low-molecular weight wax per 100 wt. parts of the polymer components.

Referenced Cited
U.S. Patent Documents
3941898 March 2, 1976 Sadamatsu et al.
4386147 May 31, 1983 Seimiya et al.
4486524 December 4, 1984 Fujisaki et al.
4883734 November 28, 1989 Ikeuchi et al.
5071918 December 10, 1991 Funato et al.
5126224 June 30, 1992 Hyosu et al.
5268248 December 7, 1993 Tanikawa et al.
5489498 February 6, 1996 Ohno et al.
Foreign Patent Documents
331015 September 1989 EPX
427272 May 1991 EPX
488413 June 1992 EPX
501768 September 1992 EPX
519715 December 1992 EPX
56-116043 September 1981 JPX
57-178249 November 1982 JPX
57-208559 December 1982 JPX
61-110156 May 1986 JPX
62-9356 January 1987 JPX
63-214760 September 1988 JPX
63-217362 September 1988 JPX
63-217363 September 1988 JPX
63-217364 September 1988 JPX
63-313182 December 1988 JPX
1-15063 March 1989 JPX
1-187582 July 1989 JPX
2-168264 June 1990 JPX
2-235069 September 1990 JPX
3-72505 March 1991 JPX
Other references
  • Patent Abstracts, Japan, vol. 14, No. 245, P-1082 (4188) May 24, 1990, JPA 02-064556.
Patent History
Patent number: 5744276
Type: Grant
Filed: Mar 30, 1994
Date of Patent: Apr 28, 1998
Assignee: Canon Kabushiki Kaisha (Tokyo)
Inventors: Manabu Ohno (Funabashi), Hiroyuki Suematsu (Yokohama), Akihiko Nakazawa (Kanagawa-ken), Nobuyuki Okubo (Yokohama), Shunji Suzuki (Tokyo)
Primary Examiner: Christopher D. Rodee
Law Firm: Fitzpatrick, Cella, Harper & Scinto
Application Number: 8/220,044
Classifications
Current U.S. Class: 430/109; 430/110
International Classification: G03G 9087;